Inlet manifold for internal-combustion engines



June 21 1927 E. R. BURTNTT INLT MANIFOLD FOR INTRNAL COMBUSTION ENGINESFiled July'sl, 1924 N l (f .\.1 m mm1 mls il Patented June 21, 1927.

UNITED STATES reszse PATENT oFFicE.

EVERETT `IR.. BURTETT,'OF LOS ANGELES, CALIFORNIA, ASSGNOR, BY DIRECTAND MESNE ASSIGNMENTS, TO THE AUTOMOTIVE VALVES CO.,- OF LOS ANGELES,CALI- FORNIA, .A VOLUNTARYiTRUST.

INLET MANIFOLD Fon IN'rnnnAncoMBusfrIoN ENGINES.

Application filed .Tuly 31, 1924. Serial No. 729,299.

My invention relates generally to internal combustion engines and moreparticularlyA lcharge being admitted through Aports uncovered by thepiston at suchtime.

lt. has been found by experiment and practice, with an engine embodyingtwo units of the two-stroke cycle principle wherein one revolution, or360, completes the cycle, and with the admission of the fuel chargetal-:ing place during the time the precompression piston passes overouter dead center, that this function occupies a total time ofapproximately 909, As there/are only two of these admission periods,itnecessarily follows that in an engine of two units, during each 360oshaftf rotation, each complete period of 90 duration, with alternateVand successive 90o non-admission periods between each of the 90'admission periods, causes, where a conventional manifold is used, a verygreat fluctuation of pressure within said manifold and necessitates theuse of a carburetor having too great a volume capacity and a manifoldwithout the necessary restriction to provide sufficient charge velocityVto develop maximum power and fuel economy in engine operation. l

` Therefore, it is an object of my invention, to provide an inletmanifold with anoutlet to each precompression unit and an inlet from thecarbureter or mixing means. In order thatthe velocity be as high as posesible, the passsageways or ducts between the inlet and outlets of themanifold are made comparatively small, so as to provide a volumecompatible with the displacement of the precompression chamber in themanifold, so that, during the short period of 90o in which the chambermust fill, I have formed a continuous passage manifold, in which thepart joining the two outlets and out of the path of direct circulationbetween the inlet and outlets is relatively large in cross section.

A further object of my invention is, to form the manifold so that therewill be no liquid traps in thefpassageways, the gravity 'drain surfacesextending Veach way from the inlet opening to the manifold, to eachoutlet opening therefrom, and gravity drain surfaces extending from thecenter of the non-inlet passage that connects the two outlets in bothdirections from center to said manifold outlets. y l

lVith the foregoing and other objects in view, my invention consists inthe features of construction and combination and ar rangement of partshereinafter more fully described and claimed,'reference being had to theaccompanying drawings, in which yFigure 1 is a top plan view of agaseous fuel inlet manifold of my improved con-l struction Figure 2 isay vertical section taken on thel line 2 -2 of Figure l;

Figure 3 is a vertical cross section taken approximately on the line 3-3of Figure 1; VFigure 4 is a vertical cross section taken approximatelyon' the line i-li of Figure 1.

My improved inletmanifold is preferably cast in a single piece, and itcomprises an upper member 10 and a lower member 11,

which members are hollow so as to provide a: practically continuouschamber.

The central portion of the upper member 10 is relatively large in crosssection so to provide a central chamber 12 of consider able area. F romthe housing that surrounds this relativelyA large central chamber, the

walls of member l() gradually decline in opposite directions toward theVends of the casting, and thus oppositely arranged declining drainsurfaces 13 are formed on the bottom walls of the end portions of thehousing, which drain surfaces startr from the center of the housing 10and gradually decline in both directions therefrom. Y

The ends of upper hollow member l unite directly with downwardly andinwardly curved hollow end members 14 and formed integral with the rearportions of the lower ends of these members 14 are rearwardly projectinglugs l that are adapted to be rigidly fixed in any suitable mannerdirectly to the cylinder block of an engine. rFliese lugs 15 areprovided with horizontally dis-l l than that of hollow member 10, andthroughout-its `length the cross sectional area of said hollow member isless than the cross sectional dimensions of said upper member l0. Aflanged opening 17 is formed at the center' of member 11 for theadmission of gaseous fuel from a carbureter or like source ofsupply,andfrom this gaseous fuel inlet the. bottom surfaces of the chamber through`member 11 decline in opposite directions to Vward the gaseous fuelinlet opening 16, there- Vby providing drain surfaces 18 that correspondwith the drain surfaces 13 in upper member l0.

Thus it will be seen that I have provided a relatively simple andpractical inlet manifold havingan outlet to each precompression unit ofthe engine and with a single gaseous fuel inlet from the carbureter or,other source of gaseous fuel supply and which inlet is located at acentral point between the outlets,`and, further, that there is arelatively large chamber between the gaseous fuel outlets. As a resultof this arrangement, the sudden demand developed by the suction strokeof one of the pistons within the engine onA the gaseous fuel Voluniewithin the manifold will notv cause an extraordinary orabnormalfluctuation of velocity and pressure on the carbureter, which result isbrought about by the large area `within the manifold and the provisionof the continuous chamber therein. y As a result, the carbilreter may berestricted so as to provide proper velocity and the desirable andadvantageous steady column movement, which latter materially assists inuniform metering of the fuel with the air.

lVhile the engine is in operation there will always be a certain amountof gaseous 4fuel within the ,chamber in the manifold,

and as this chamber is endless and portions thereof extend in twodirections from each gaseous fuel outlet port, there will beuvery reterthat supplies said manifold with fuelVK will function to `developmaximum power and fuel economy duringengine operation. Inasmuch as thebottom surfaces of both upper andlower members `of the manifold declinein both directions away from the center, any condensation that may takeplace on the inner surfaces of the walls of the manifold will eventuallyflow by gravity downwardly over the drain surfaces and will pass,through the out-let port-s `16 to the combustion chambers within theengine.

An inlet manifold 'of my improved con struction is comparatively simple,may be easily and cheaply produced and is very effect-ive in performingits intendedfunctions.

I claim as my invention: y 1. A gaseous fuel inlet manifold comprisinga. housing having upper and lower cliambers,.one of which is arrangeddirectly above the other, the ends of which are connected by shortvertically disposed curved ducts, the p upper chamber being substantially larger in area than the lower chamber, the connected ends of thetwo chambers being provided with outlet openings, the intermediateportion of the lower chamber being provided with an inlet openingand thebottom surfaces of both chambersbeing formed so as to` provide'gravitydrainage from their intermediate portions toward y' both 4of said outletopenings. t

2. A gaseous fuel inletmanifold havingr upper and lower chambers, one ofVwhich `is arranged directly above the other-,the upper chamber beingsubstantially larger than the lower chamber, the ends of said chambers lhaving t communication with each other `by means'tof short verticallydisposed curved ducts, Vthe bottom surface` ,of the upper chamber beingformed so `that it gradually declines from `a centralV point towardbothends,` the ends of the lower chamber being lprovided kwith outletopenings, the central portion/of said lower `chamber being Vprovidedwith an inlet opening and the bottom surface of which lower chambergradually declines from the centrally arranged inlet opening toward saidoutlet. openings. p

Intestimony whereof I affix my signature.

. EVERETT R. BURTNETT.`

